1. Field of the Invention
The present invention relates to a hinge device for a portable wireless terminal, and more particularly to a rotary type hinge device of biaxial rotation, which enables the reversal of front and rear surfaces of a folder, opened away from a terminal body of a portable wireless terminal, while rotating relative to the terminal body.
2. Description of the Related Art
Generally, portable wireless terminals are classified into bar type terminals, flip type terminals and folder type terminals, in accordance with an external form thereof.
The bar type terminals are configured so that a single body housing thereof is provided with data input and output means including receiver and transmitter modules. In the case of the bar type terminals, there is a disadvantage that a keypad, as data input means, is always exposed to accidental misuse and damage that may cause the keypad to malfunction. In addition, the bar type terminals are limited in extent of their miniaturization due to a technologically required minimal distance between the receiver and transmitter modules.
The flip type terminals generally comprise a terminal body, a flip cover, and a hinge device adapted to rotatably couple the flip cover to the terminal body. The terminal body is mounted with data input and output means including receiver and transmitter modules. The flip cover serves as a cover for a keypad, which is a data input means, thereby preventing the mistreatment and eventual malfunctioning of the keypad. However, the flip type terminals are still limited in their miniaturization due to a technologically required minimal distance between receiver and transmitter modules thereof.
The folder type terminals generally comprise a terminal body, a folder, and a hinge device adapted to rotatably couple the folder to the terminal body. The folder is adapted to be opened away from or closed towards the terminal body according to its rotation relative to the terminal body. In a folded state wherein the folder is in contact with the terminal body, the portable wireless terminal is in a call waiting mode while preventing the damage to or malfunction of a keypad as data input means mounted on the terminal body. Further, in an unfolded state wherein the folder is rotated to an open position, the portable wireless terminal is in a conversation mode while ensuring a sufficient distance between transmitter and receiver modules, thereby advantageously miniaturizing the terminal. For this reasons, popularity of such folder type terminals is on the rise.
Those skilled in the art will easily appreciate such bar type, flip type or folder type terminals classified as stated above.
The hinge device provided in the flip type or folder type terminals and adapted to rotatably couple the flip cover or folder to the terminal body, is configured to cause the flip cover or folder to be forced toward its open position. The hinge device achieves that without requiring any additional external force when the flip cover or folder is opened away from the terminal body exceeding a predetermined angle. When the angle formed by the flip cover or folder is below the predetermined angle, the flip cover or folder is forced by the hinge device to come into close contact with the terminal body.
The conventional hinge device for use in the flip type or folder type portable wireless terminals is disclosed in U.S. Pat. No. 6,292,980, granted to the applicant of the present invention. The hinge device, disclosed in that patent comprises a hinge cam and hinge shaft, which are formed with mountain-shaped portions or valley-shaped portions, respectively, and a hinge spring received in a hinge housing and adapted to urge the hinge cam to come into close contact with the hinge shaft. The hinge device is designed to open and close a flip cover or folder of a portable wireless terminal by means of circumferentially curved surfaces of the mountain-shaped and valley-shaped portions and by means of elastic force of the hinge spring.
Although functions of the portable wireless terminals have rapidly expanded as mobile services have become increasingly diversified, the conventional hinge device has not varied its function of simply causing the flip cover or folder of the portable wireless terminal to be opened away from or closed to the terminal body. This causes many limitations in specifications and abilities of portable wireless terminals. For example, there are limitations in the addition of certain devices, such as a camera lens, to the terminals for enabling users of such terminals to utilize various available and anticipated mobile services. Specifically, in the case of the camera lens, it is difficult to harmonize an image capturing direction of the camera lens with an image display direction of a display device provided in the portable wireless terminal. In addition to limitations of the specification and design of terminals, the conventional hinge device has a disadvantage, it can't satisfy ever more diverse customers' tastes, and increasingly diversified mobile services.